Method of preparing building units



Patented 'Mar. 10,1925.

UNITED. STATES PATENT-OFFICE.

WILLIAM A. IBM, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOB TO NA- TIONAL LIME ASSOCIATION, OF WASHINGTON, DISTRICT OF COLUMBIA, A- COR- PORATION OF EHE DISTRICT OF COLUMBIA.

mnon OF PREPARING BUILDING UNITS.

Rb Drawing.

To all whom it may concern:

Be it known that I, WILLIAM A. Fmcan'r, a citizen of the United States, and resident of Washington, in the District of Columbia, have invented certain new and useful Improvements in Methods of Pre aring Building Units, of which the following is aspecification.

My present invention relates to building units and to the process of producing the same.

My invention concerns particularl a method of preparation of such units w ere cement, lime, gypsum, or combinations of any or all of the above, are used as the cementitious binders.

It has been found impossible in the past to produce building units havin perforations or apertures there-in in whic lime, cement, or gypsum are used as the cementitious or binding agent, by an extrusion process. It has long been the practice to form clay bricks by this process, in fact many particular advanta es accrue as a result from the use of sue a process in the production of building units of clay.

It has also been known that mixtures containing lime, cement, or gypsum, when in a.

fluid, semi-fluid, or plastic mass, are brought into contact with machines of the type used for extruding clay bricks commonly made of iron or alloys thereof, that the mass tends to stick and adhere to the parts of the machine to such an extent that the machine is clogged and the work cannot be continued without thorou hly cleaning off the adhering particles. Sue machines can only make comparatively few blocks and, therefore, the repeated cleaning made necessa makes the process of extrusion, when use with these materials, impracticable. I

The affinity of lime, cement or gypsum for iron and its alloys, is such that once the material begins to solidify on these metallic parts, water will not wash it o-fl, but it be comes necessary to chisel, scrape, or otherwise forcibly separate the two materials. The condition of the surface of the iron apparently has no effect upon the de ree of affinity of these materials'therefor. or instance, a machine havin a polished steel aperture would not extru e blocks in which lime was'the binding agent for a time appreciably longer than the same machme pro- Application filed August 22, was. Serial in. 658,841.

vided with an aperture made of cast iron having an unfinished surface. I do not attempt to explain the nature of this aflinity which makes itself so manifest under these conditions, and which has heretofore limited the production of blocks in which cement, lime orgypsum were used as a cementitious agent, to an operation which includes pressing, tamping, pouring or formlng within a mould-like structure.

I have discovered, however, that if the ordinary machine of the type commonly been found to have no unusual aflinity for lime, cement or gypsum, are co per, tin, aluminum and nickel. Various alloys containing these elements have been also found to give very satisfactory results.

I do not prefer any particular form of devicefor carrying out my invention, as any extrusion machine of a type adapted to produce building blocks may be used, provided its extrusion orifice and other parts comin in contact with the material being extruded include any of the above non-ferrous metals in their composition to a substantial degree. It wlll be obvious that combinations of iron and the above, may be used where the nonferrous metal is present in a sufiicient quantity to outeigh the undesirable characteristics of the errous material. However, I am not at present informed of the preferred composition or combination of ferrous and non-ferrous material which produces the most efiicient results. It will be readily seen that the presence of ferrous material to an appreciable extent will detract from the efficiency of the machine and the rocess, b introducing the undesirable quai herence.

It may be found desirable in some cases, to apply heat to the extruded block before being used as a building element. Obviously such heat, where found desirable, may be applied either in the machine as the block is being extruded, or afterwards. The

former has the advantage of confining this ity of a step to the operation of extrusion and does I not. require separate handling.

What I claim is 1. A process of producing building units which includes the step of extruding a plastic mass containing a compound of calcium through an orifice, the surface in contact with said mass comprising a non-ferrous metal. 2. A process of producing building units which includes the step of extruding a plastic mass containing a compound of calcium through an orifice, the surface in contact with said mass including copper.

3. A. process of producing building units which includes the step of extruding a plastic mass containing a compound of calcium through an orifice, the surface in contact with said mass including an allo of copper.

4. A process of producing bullding units which includes the step of extrudin a plastic mass containing a compound 0 calcium through an orifice, the surface in contact with said mass includin brass.

ture.

' WILLIAM FRERET.

In testimony whereo I aflix my signa- 25 

